[PULL 25/26] target/arm: Enable SCTLR_EL1.TIDCP for user-only

[Peter Maydell <peter.maydell@linaro.org>]

From: Richard Henderson <richard.henderson@linaro.org>

The linux kernel detects and enables this bit.  Once trapped,
EC_SYSTEMREGISTERTRAP is treated like EC_UNCATEGORIZED, so
no changes required within linux-user/aarch64/cpu_loop.c.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20230831232441.66020-6-richard.henderson@linaro.org
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
---
 target/arm/cpu.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/target/arm/cpu.c b/target/arm/cpu.c
index 0bb05854419..b9e09a702d6 100644
--- a/target/arm/cpu.c
+++ b/target/arm/cpu.c
@@ -243,6 +243,10 @@ static void arm_cpu_reset_hold(Object *obj)
                                   SCTLR_EnDA | SCTLR_EnDB);
         /* Trap on btype=3 for PACIxSP. */
         env->cp15.sctlr_el[1] |= SCTLR_BT0;
+        /* Trap on implementation defined registers. */
+        if (cpu_isar_feature(aa64_tidcp1, cpu)) {
+            env->cp15.sctlr_el[1] |= SCTLR_TIDCP;
+        }
         /* and to the FP/Neon instructions */
         env->cp15.cpacr_el1 = FIELD_DP64(env->cp15.cpacr_el1,
                                          CPACR_EL1, FPEN, 3);
-- 
2.34.1